Electric water heater



Patented Jan. 18, 1927.

UNITED STATES PATENT OFFICE.

ERNEST E. KITTREDGE, JOSEPH A. FORSTER, AND RASMUS D. JOHANSEN, OF

ALAMEDA, CALIFORNIA.

ELECTRIC WATER HEATER.

Application filed May 6,

Our invention is an induction electric water heater operating on the principle of a transformer. The primary coils of an iron core transformer are formed of wires in the usual way and the secondary comprises a coil of pipe around the core, allowing a fluid such as water to pass therethrough. The secondary is short circuited to develop heat.

In its preferred form our heater is used as an instantaneous heater, in which the opening of a faucet closes a switch in the primary circuit whereby the water is heated.

Our invention can be more readily understood from the following description and drawings in which 2-- Figure 1 is a side view of an instantaneous type of heater in which the electric switch is operated by the flow of water.

Figure 2 a front view, portions being shown in section.

In the drawing the transformer is indicated generally by the numeral 1 and is composed of an iron core 2, having the primary windings 3 of wire and secondary windings 1 of hollow tubes A short cireuiting bar 5 connects the two ends of the secondary. A. suitable box 16 encloses the transformer, while the insulation 9 surrounds the trans former. A water inlet 17 is carried through an automatic valve 18 for controlling the electric switch 19 in the primary circuit 20 which is connected to any suitable source of current. The water outlet 21 is controlled by a faucet 22.

The operation of our induction water heater is as follows :-lVhen the water is turned on at the faucet 22, it alters the pressure in the automatic valve 18 and closes the electric switch 19. The electric current therefore passes through the primary winding 3 and causes an induced current in the secondary winding 4., made of coiled pipes surrounding the core 2. The Water from the inlet 17 passes into the secondary from whence it is led to the faucet 22. The water is heated as soon as it begins to flow, the temperature to a certain extent being regulated by the rapidity of the flow of Water. hen

the faucet is closed the automatic valve 18 1925. Serial N0. 28,336.

operates to open the switch 19, thereby breaking the electric circuit.

Our invention may be put to a variety of uses such as generating steam and heating various liquids and gases. The details of construction can be materially altered to suit various circumstances without departing from the spirit of our invention. The an'i-ount of heat generated in the secondary may be calculated with suiiicient exactness by well known formula dealing with electric transformers, and thereby the rate of heating the water or other fluid may be predetermined.

Our invention comprehends a method of heating fluids or gases by an induction cur rent in which the current passes through the tubes in which the fluid or gases are flowing, and with certain fluids having conductive properties, the electric current will be conducted in the body of such fluids or gases and thereby directly heat them.

As a modification of our invention, the secondary coil tubes can be made of nonconducting material, and a conducting gas or fluid being passed therethrough', will carry the induced current. In such case a short circuit connection could be made outside of the coil proper between the conducting fluids or gases.

Having described our invention what we claim is An electric heater comprising a transformer having a tubular secondary coil, an inlet pipe and an outlet pipe connected to said coil, a short circuit bar connecting the ends of said coil, electric and heat insulation enveloping said transformer, a faucet in said outlet pipe, an automatic valve in said inlet pipe, a switch in the primary circuit of said transformer and connecting means between said switch and said valve whereby the opening of said faucet causes said valve to close said switch.

In testimony whereof we affix our signa tures.

ERNEST E. KITTR-EDGE. JOSEPH A. FORSTER. RASMUS D. JOHANSEN. 

